Photoelectron diffraction structure determination of Cu(1 0 0)c(2×2)-N

Using scanned-energy mode photoelectron diffraction of the N 1s photoemission, combined with multiple scattering modelling calculations, the structure of the Cu(1 0 0)c(2×2)-N has been investigated. While the results are broadly consistent with N adsorption in a fourfold coordinated hollow site, almost coplanar with the outermost layer, this model can only be fitted to the data with unphysically large vibrational amplitudes, strongly suggesting that some static adsorbate-induced substrate distortion is involved. The best-fit structure involves an unusual symmetry-lowering large amplitude (0.34 إ) rumpling of the outermost Cu layer. This result is entirely consistent with the results of a recent scanning tunnelling microscopy study of this surface.